Recently, broadcasting systems have been used which are able to convert an NTSC video signal into a PAL video signal, and vice versa. Such systems have been used in conformity with a trend towards broadcasting internationalization. However, the video signal processing systems which have been adapted for use with an NTSC system and a PAL system include separate sync separators for each broadcasting system. Accordingly, the circuitry of the system is rather complex. In addition, since detection of an odd and even field is processed using software employed in a microcomputer, it is difficult to obtain an exact output.